Is this bell the original or a recast?

[ticktocktwang]

Hi all, 

I would be grateful for your expert opinions regarding originality or not of a bell.  The bell is a singleton bell and was originally cast by the Murphy Foundry, Dublin in 1843 for Tuam RC Cathedral, in the west of Ireland. What makes it interesting is that it is the earliest known bell by Murphy.  However, as can be seen in the photos (See Files Section, Folder "Tuam RC Bell") the bell has a "Byrne Patent Rotary Mounting," which apparently was not patented until 1887.  Bells by Byrne had a tapered boss through which the mounting was attached to the bell.  Such a boss is not evident on the Tuam RC bell but neither are there any cannons.  My query is:  are the "ridges" (apologies for lack of a better term) on the Tuam RC bell, the remnants of cannons that could justify the bell as being original, or are these ridges artefacts of the bell-making process (I know very little about bell manufacture!!) which might suggest that this is a recast bell by Byrne with the original Murphy signature and trade emblem included?  

Many thanks for reading this.